This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A063933 #10 Jun 24 2018 21:00:14
%S A063933 0,0,0,0,0,0,-1,0,1,0,0,0,-1,0,1,0,0,0,-1,0,1,0,-2,-1,0,1,2,0,0,0,-2,
%T A063933 -1,0,1,2,0,-1,0,1,0,0,0,-1,0,1,0,-2,-1,0,1,2,0,-2,-1,0,1,2,0,0,0,-2,
%U A063933 -1,0,1,2,0,-1,0,1,0,0,0,-2,-1,0,1,2,0,-1,0,1,0,-2,-1,0,1,2,0,-3,-2,-1,0,1,2,3,0,-1,0,1,0,0,0,-1,0,1,0,0,0,-1,0,1,0
%N A063933 Difference between n and the average of largest prime less than or equal to n and smallest prime greater than or equal to n.
%H A063933 Harry J. Smith, <a href="/A063933/b063933.txt">Table of n, a(n) for n = 2..1000</a>
%F A063933 a(n) = n - (A007917(n) + A007918(n))/2 = n - A063932(n).
%F A063933 a(n) = 0 for numbers in A063934 (i.e., in A000040 or A024675).
%e A063933 a(10) = 10 - (11 - 7)/2 = 1; a(11) = 11 - (11 + 11)/2 = 0.
%o A063933 (PARI) { for (n=2, 1000, write("b063933.txt", n, " ", n - (precprime(n) + nextprime(n))/2) ) } \\ _Harry J. Smith_, Sep 03 2009
%K A063933 sign
%O A063933 2,23
%A A063933 _Henry Bottomley_, Aug 21 2001